In a front wheel drive vehicle, generally, the rear suspension system includes a wheel hub assembly for installing the wheel in a manner capable of idle revolutions, a trailing arm for securing the wheel hub assembly to the vehicle body in the lengthwise direction, and upper and lower arms for supporting the wheel hub assembly to the vehicle body in the lateral direction.
In conventional rear suspension systems, the braking force generated by friction between the wheels and the road surface during braking is imposed from the front of the wheels, the wheels being installed on the wheel hub assemblies. Accordingly, the wheels tend to pivot the trailing arms outward from the vehicle body.
This phenomenon makes the wheel alignment varied from tow-in to tow-out. If this occurs, the stability of the vehicle is jeopardized when the vehicle brakes or turns during movement.